Air cylinder



FIG. 1 is a front elevational view of an air cylinder showing my new design;

FIG. 2 is a right side elevational view;

FIG. 3 is a left side elevational view;

FIG. 4 is a top plan view;

FIG. 5 is a bottom plan view;

FIG. 6 is a cross sectional view taken along the lines 6--6 of FIG. 2; and,

FIG. 7 is a perspective view. 

The ornamental design for an air cylinder, as shown. 